2G4 



THE SKIN 



Cylindrical Cell Layer (Stratum CyUndricum).The deepest cells 

 of the stratum mucosum are elongated in a direction nearly perpendicu- 



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FIG. 261. SECTION OF THIN SKIN FROM ABDOMEN OF NEGRO, SHOWING THE DISTRI- 

 BUTION OF THE PIGMENT GRANULES IN DERMAL AND EPIDERMAL CELLS. X 750. 



lar to the basement membrane upon which they rest; they are thus 

 irregularly cylindrical in shape. It is these cells which in the pig- 



mented portions of 

 the body, i.e., areo- 

 Ia3 of the nipples, 

 s c r o t u m, circu- 

 manal region, etc., 

 and in the skin of 

 brunettes and the 

 colored races con- 

 tain the pigment 

 which gives rise to 

 the darkened color 

 of the skin. 



In the skin of 

 the negro, the pig- 

 ment (m e 1 a n i c) 

 granules, while 



most abundant in the basal cylindrical cells, are nevertheless present, but 

 in progressively smaller number, in all of the outer cell layers. In the 



FIG. 262. SECTION OF THIN SKIN FROM ABDOMEN OF 

 LIGHT BROWN MULATTO. X 750. 



